When you're at the supermarket and start reversing, only for the car parked in the next bay across behind you, to start doing the same ... so you pull back into your park to let them go first, and they do the same. So, you wave in your rear-view mirror for them to come out and they just sit there for what seems like an eternity ... so you start reversing again ... as do they. So, you pull back into your park again, as do they, and this goes on and on, until you just think, "Feck it, I'm going to stay parked up until they vacate their park"!